This invention pertains generally to arrangements for controlling the orientation of movable elements within a body, and particularly to an arrangement for precisely controlling a gimbal for a gyroscopically stabilized antenna.
The continuing development of components for radar has recently made it feasible to design and produce systems which operate in the so-called "millimeter region," i.e., systems having an operating frequency band encompassing 94 GHz. However, along with the advantages such as the relatively small size and weight of such types of radar, new and hiterto unrecognized problems have arisen. For example, when the antenna for a radar is mounted on a gyroscopically stabilized platform (as in a target seeker in a projectile or missile), known types of control circuitry are inadequate. That is to say, because the width of the radar beam of a radar operating at 94 GHz may be extremely narrow, known ways to control the orientation of a gyroscopically stabilized platform so that such a beam may track a target are not sufficiently accurate for satisfactory operation. In addition, when it is desired to use a digital computer to process signals out of a radar having a gyroscopically stabilized antenna, it is necessary that the instantaneous rotational position of the rotor of the gyroscope motor must be monitored. That is to say, that rotor must be phase-locked to the master clock signal of the digital computer.